One of the most intriguing and important cookbooks published this year. Ruhlman (The Soul of a Chef) is a food poet, and the pig is his muse. On witnessing a plate of cold cuts in Italy, he is awed by "the way the sunlight hit the fat of the dried meats, the way it glistened, the beauty of the meat." He relates and refines the work of Polcyn, a chef-instructor at a college in Livonia, Mich., who butchers a whole hog "every couple weeks for his students." Together, they make holy the art of stuffing a sausage, the brining of a corned beef and the poaching of a salted meat in its own fat. An extensive chapter on p?t?s and terrines is entitled "The Cinderella Meat Loaf" and runs the gamut from exotic Venison Terrine with Dried Cherries to hearty English Pork Pie with a crust made from both lard and butter. And while there's no shortage of lyricism, science plays an equally important role. Everyone knows salt is a preservative, for example, but here we learn exactly how it does its job. And a section on safety issues weighs the dangers of nitrites and explains the difference between good white mold and the dangerous, green, fuzzy stuff. Line drawings.